<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html><head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Commit And Rollback Notification Callbacks</title>
<style type="text/css">
body {
    margin: auto;
    font-family: Verdana, sans-serif;
    padding: 8px 1%;
}

a { color: #044a64 }
a:visited { color: #734559 }

.logo { position:absolute; margin:3px; }
.tagline {
  float:right;
  text-align:right;
  font-style:italic;
  width:300px;
  margin:12px;
  margin-top:58px;
}

.toolbar {
  text-align: center;
  line-height: 1.6em;
  margin: 0;
  padding: 0px 8px;
}
.toolbar a { color: white; text-decoration: none; padding: 6px 12px; }
.toolbar a:visited { color: white; }
.toolbar a:hover { color: #044a64; background: white; }

.content    { margin: 5%; }
.content dt { font-weight:bold; }
.content dd { margin-bottom: 25px; margin-left:20%; }
.content ul { padding:0px; padding-left: 15px; margin:0px; }

/* rounded corners */
.se  { background: url(../images/se.gif) 100% 100% no-repeat #044a64}
.sw  { background: url(../images/sw.gif) 0% 100% no-repeat }
.ne  { background: url(../images/ne.gif) 100% 0% no-repeat }
.nw  { background: url(../images/nw.gif) 0% 0% no-repeat }

/* Things for "fancyformat" documents start here. */
.fancy img+p {font-style:italic}
.fancy .codeblock i { color: darkblue; }
.fancy h1,.fancy h2,.fancy h3,.fancy h4 {font-weight:normal;color:#044a64}
.fancy h2 { margin-left: 10px }
.fancy h3 { margin-left: 20px }
.fancy h4 { margin-left: 30px }
.fancy th {white-space:nowrap;text-align:left;border-bottom:solid 1px #444}
.fancy th, .fancy td {padding: 0.2em 1ex; vertical-align:top}
.fancy #toc a        { color: darkblue ; text-decoration: none }
.fancy .todo         { color: #AA3333 ; font-style : italic }
.fancy .todo:before  { content: 'TODO:' }
.fancy p.todo        { border: solid #AA3333 1px; padding: 1ex }
.fancy img { display:block; }
.fancy :link:hover, .fancy :visited:hover { background: wheat }
.fancy p,.fancy ul,.fancy ol { margin: 1em 5ex }
.fancy li p { margin: 1em 0 }
/* End of "fancyformat" specific rules. */

</style>
  
</head>
<body>
<div><!-- container div to satisfy validator -->

<a href="../index.html">
<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite Logo"
 border="0"></a>
<div><!-- IE hack to prevent disappearing logo--></div>
<div class="tagline">Small. Fast. Reliable.<br>Choose any three.</div>

<table width=100% style="clear:both"><tr><td>
  <div class="se"><div class="sw"><div class="ne"><div class="nw">
  <table width=100% style="padding:0;margin:0;cell-spacing:0"><tr>
  <td width=100%>
  <div class="toolbar">
    <a href="../about.html">About</a>
    <a href="../sitemap.html">Sitemap</a>
    <a href="../docs.html">Documentation</a>
    <a href="../download.html">Download</a>
    <a href="../copyright.html">License</a>
    <a href="../news.html">News</a>
    <a href="../support.html">Support</a>
  </div>
<script>
  gMsg = "Search SQLite Docs..."
  function entersearch() {
    var q = document.getElementById("q");
    if( q.value == gMsg ) { q.value = "" }
    q.style.color = "black"
    q.style.fontStyle = "normal"
  }
  function leavesearch() {
    var q = document.getElementById("q");
    if( q.value == "" ) { 
      q.value = gMsg
      q.style.color = "#044a64"
      q.style.fontStyle = "italic"
    }
  }
</script>
<td>
    <div style="padding:0 1em 0px 0;white-space:nowrap">
    <form name=f method="GET" action="http://www.sqlite.org/search">
      <input id=q name=q type=text
       onfocus="entersearch()" onblur="leavesearch()" style="width:24ex;padding:1px 1ex; border:solid white 1px; font-size:0.9em ; font-style:italic;color:#044a64;" value="Search SQLite Docs...">
      <input type=submit value="Go" style="border:solid white 1px;background-color:#044a64;color:white;font-size:0.9em;padding:0 1ex">
    </form>
    </div>
  </table>
</div></div></div></div>
</td></tr></table>
<div class=startsearch></div>
  
<a href="intro.html"><h2>SQLite C Interface</h2></a><h2>Commit And Rollback Notification Callbacks</h2><blockquote><pre>void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
</pre></blockquote><p>
The sqlite3_commit_hook() interface registers a callback
function to be invoked whenever a transaction is <a href="../lang_transaction.html">committed</a>.
Any callback set by a previous call to sqlite3_commit_hook()
for the same database connection is overridden.
The sqlite3_rollback_hook() interface registers a callback
function to be invoked whenever a transaction is <a href="../lang_transaction.html">rolled back</a>.
Any callback set by a previous call to sqlite3_rollback_hook()
for the same database connection is overridden.
The pArg argument is passed through to the callback.
If the callback on a commit hook function returns non-zero,
then the commit is converted into a rollback.</p>

<p>The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
return the P argument from the previous call of the same function
on the same <a href="../c3ref/sqlite3.html">database connection</a> D, or NULL for
the first call for each function on D.</p>

<p>The commit and rollback hook callbacks are not reentrant.
The callback implementation must not do anything that will modify
the database connection that invoked the callback.  Any actions
to modify the database connection must be deferred until after the
completion of the <a href="../c3ref/step.html">sqlite3_step()</a> call that triggered the commit
or rollback hook in the first place.
Note that running any other SQL statements, including SELECT statements,
or merely calling <a href="../c3ref/prepare.html">sqlite3_prepare_v2()</a> and <a href="../c3ref/step.html">sqlite3_step()</a> will modify
the database connections for the meaning of "modify" in this paragraph.</p>

<p>Registering a NULL function disables the callback.</p>

<p>When the commit hook callback routine returns zero, the <a href="../lang_transaction.html">COMMIT</a>
operation is allowed to continue normally.  If the commit hook
returns non-zero, then the <a href="../lang_transaction.html">COMMIT</a> is converted into a <a href="../lang_transaction.html">ROLLBACK</a>.
The rollback hook is invoked on a rollback that results from a commit
hook returning non-zero, just as it would be with any other rollback.</p>

<p>For the purposes of this API, a transaction is said to have been
rolled back if an explicit "ROLLBACK" statement is executed, or
an error or constraint causes an implicit rollback to occur.
The rollback callback is not invoked if a transaction is
automatically rolled back because the database connection is closed.</p>

<p>See also the <a href="../c3ref/update_hook.html">sqlite3_update_hook()</a> interface.
</p><p>See also lists of
  <a href="objlist.html">Objects</a>,
  <a href="constlist.html">Constants</a>, and
  <a href="funclist.html">Functions</a>.</p>
